1. Overview of Sensor Networks David Culler Deborah Estrin Mani Srivastava

2. Wireless Sensor Network ► Result of Moore ’ s Law ► Limited processing speed, storage capacity, communication bandwidth, energy source ► Complex interaction between nodes ► Easy deployment and maintenance

3. Wireless Sensor Network ► Applications:  Monitoring space  Monitoring things  Monitoring interaction of things with each other and environment

4. Environmental Monitoring ► Monitoring redwood trees: UC Berkeley http://www.sfgate.com

5. Motion Monitoring ► Monitor motion, vibration, acoustic emissions … etc ► Local processing with continuous communication ► Signal processing with summary communication ► Need for real-time interactions between nodes

6. Embedded Network Technology ► Microprocessor: 1mW, 10MHz ► Power source:  Solar cells: 10mW/cm 2 outdoor  Mechanical: 100  W  Battery: 1000mAh ► Memory:  10KB RAM  100KB ROM

7. Embedded Network Technology ► Microsensors: convert changes in electrical characteristics into digital signals ► Microelectromechanical systems (MEMS) ► Microradios iMEMS Accelerometer showing Structural beam and surrounding electronics Close up of iMEMS acceleration sensor http://www.analog.com

8. TinyOS ► Component-based, event-driven OS  Interfaces: Commands and Events  Wiring: Modules and Configurations ► Concurrency model  Executes one program only  Tasks and Event handlers

9. Network Sensor Platforms ► Mica motes  Simple, constrained hardware ► Intel motes  Enhanced version of Mica  ARM processors  Bluetooth radios http://www.xbow.com http://www.intel.com

10. Network Sensor Platforms ► Stargate Gateway  400MHz, Xscale processor  PCMCIA, CF card, Ethernet, Serial, JTAG, USB compatible  “ Used as points of aggregation, data storage, data fusion, and hosts for higher-end sensors. ” http://www.xbow.com

11. Self-organized Networks ► Organized as mesh network  Routing is adaptive to changing environment ► Dissemination and Data collection  Epidemic protocols  Directed diffusion – interest pub/sub model  DTN – reliable hop-by-hop delivery

12. Power and Bandwidth ► Possible approaches  Turn off radio when not needed  Low powered component wakes up the system  Perform local processing and transmit summary  Compression and scheduling

13. Privacy ► Data travels in unsecured medium ► Various attacks are possible ► Access control to data is often important

14. Applications ► PinPtr: Shooter Localization in Urban Tarrain  Ad-hoc acoustic WSN  Measures muzzle blast and shockwave http://disco.informatik.uni-kl.de

15. Visions ► Sensors will become more pervasive ► Cost of sensors will continue to decrease ► Energy will be harvested from environment ► Newer language / signal processing support

16. References ► http://www.tinyos.net http://www.tinyos.net ► http://www.xbow.com http://www.xbow.com ► http://www.intel.com/research/exploratory/motes.htm http://www.intel.com/research/exploratory/motes.htm ► http://www.sfgate.com/cgi- bin/article.cgi?f=/c/a/2003/08/18/MN299322.DTL http://www.sfgate.com/cgi- bin/article.cgi?f=/c/a/2003/08/18/MN299322.DTL http://www.sfgate.com/cgi- bin/article.cgi?f=/c/a/2003/08/18/MN299322.DTL ► http://www.analog.com/Analog_Root/sitePage/mainSectionCont ent/0,2132,level4%253D%25252D1%2526ContentID%253D753 7%2526Language%253DEnglish%2526level1%253D212%2526l evel2%253D%25252D1%2526level3%253D%25252D1,00.html http://www.analog.com/Analog_Root/sitePage/mainSectionCont ent/0,2132,level4%253D%25252D1%2526ContentID%253D753 7%2526Language%253DEnglish%2526level1%253D212%2526l evel2%253D%25252D1%2526level3%253D%25252D1,00.html http://www.analog.com/Analog_Root/sitePage/mainSectionCont ent/0,2132,level4%253D%25252D1%2526ContentID%253D753 7%2526Language%253DEnglish%2526level1%253D212%2526l evel2%253D%25252D1%2526level3%253D%25252D1,00.html ► http://www.cs.rutgers.edu/~rmartin/teaching/fall04/cs552/lectur es/route-paradigms.pdf http://www.cs.rutgers.edu/~rmartin/teaching/fall04/cs552/lectur es/route-paradigms.pdf http://www.cs.rutgers.edu/~rmartin/teaching/fall04/cs552/lectur es/route-paradigms.pdf ► http://www.cse.ogi.edu/~wuchi/Teaching/CSE506/papers/14/sli des.ppt http://www.cse.ogi.edu/~wuchi/Teaching/CSE506/papers/14/sli des.ppt http://www.cse.ogi.edu/~wuchi/Teaching/CSE506/papers/14/sli des.ppt ► http://disco.informatik.uni- kl.de/courses/moco/Applications/Shooter_Loc_Computer.pdf http://disco.informatik.uni- kl.de/courses/moco/Applications/Shooter_Loc_Computer.pdf http://disco.informatik.uni- kl.de/courses/moco/Applications/Shooter_Loc_Computer.pdf